1. Field of the Invention
The present invention relates generally to systems for recording operational camera data and particularly to a system for electronically storing exposure information contemporaneously with the exposure of film within a camera to be later transferred to a printed paper tape record in human readable form.
2. Description of the Prior Art
There exist many disclosures of methods and apparatus for recording various exposure criteria contemporaneously with the frame-by-frame exposure of film within a camera. The most rudimentary method was often to be found on early snapshot cameras and consisted generally of a narrow closed slit in the back of the camera which could be opened revealing the paper backing on the film. The person taking the picture could then use a pencil or pen and write the desired information directly on the backing of the film at the time of exposure. This method left much to be desired and with the advent of new camera designs was no longer feasible.
Two more modern methods of recording the exposure data on the film negative and/or slide film are variations of a central concept of photographically recording the information by exposing the film to an appropriately formatted set of numbers. One such system employs a series of stencils. Upon the exposure of the film, a small amount of light projects through the stencil forming an image on the film adjacent to the exposed frame on the film. The stencils are typically manually set but can also be mechanically linked to the various camera controls in such a way as to ensure correct recording to the various film exposure criteria.
A similar method substitutes light-emitting diodes (LEDs) for the stencils and various electronic circuits for the mechanical linkages. The LEDs are then caused to emit light onto a preselected portion of the film adjacent to the exposed frame and thus record the exposure data on the film.
A common problem of the last two methods is the loss of data by mounting the negative or slide film in standard slide mounts thereby masking the area in which the information is recorded. Loss of film image within the exposed frame also is encountered due to light diffusion from the LEDs or the stencils used to record the information or due to having information erroneously recorded in the image recording area of the film. Only rarely has the prior art considered the associated problem with this type of data recording which results from the various sensitivities of different types of film. Finally, a common problem is the unavailability of the recorded information prior to development of the film. Since the information itself might be valuable with respect to the development times and procedures to be used to obtain maximum image results, the photographic recording of exposure information proves itself to be totally unsatisfactory.
Examples of prior art systems are to be found in the following U.S. Pat. Nos. 4,053,909; 4,025,931; 4,001,846; 3,971,049; 3,968,505; 3,953,868; 3,906,523; 3,889,281; 3,858,967; 3,827,070; 2,907,985; and 2,821,124.
It is accordingly one object of the present invention to have an apparatus which records the film exposure information contemporaneously with the frame-by-frame exposure of the film within the camera but makes this information available prior to the development of film. It is a further object of the present invention to provide an apparatus for recording film exposure information which has no possibility of interfering with the desired picture intended to be captured by the exposed frame of film. Another object of the invention is to utilize electronic memory circuits to record the information relating to film exposure until such time as printout of the information is convenient. It is another object of the present invention to have a major portion of the apparatus incorporated within the body of the camera itself with the printing mechanism and associated electronics being a separate unit readily attachable to the camera at convenient periodic intervals.